Feed mechanism for presses

ABSTRACT

A feed mechanism for feeding workpieces separately to a press comprising a base and a reciprocable feeding assembly. The feeding assembly embodies pusher means arranged to engage the lowermost workpiece in a stack of workpieces situated in a hopper on the base so that on reciprocation of said assembly, the pusher means pushes said lowermost workpiece forwardly to an intermediate station on the base. The feeding assembly also includes a pair of calipers adapted at their leading ends to move between open and closed positions so that in the closed position a workpiece previously deposited at said intermediate station will be gripped by the calipers and moved forwardly to the press in which it is to be deposited. Means are provided to open the calipers when the feeding assembly is at the end of its forward stroke in order that the workpiece carried by the calipers will be dropped into the press. The feeding assembly then returns to its rearward position so that the calipers can again pick up from said intermediate station another workpiece deposited there by said pusher means on the previous stroke of the feeding assembly.

ilnite States atet [111 3,750,806

artieet Aug. 7, 1973 FEED MECHANISM FOR PRESSES a press comprising abase and a reciprocable feeding [75] inventor: Leslie John Bartleet,Walsall, assembly The feeding assembly embodies P England means arrangedto engage the lowermost workpiece 1n a stack of workpieces situated in ahopper on the base Asslgnefi Unis Machine Tools Limited, so that onreciprocation of said assembly, the pusher Brownl'lills, W LE s meanspushes said lowermost workpiece forwardly to [22] Filed: Oct 5, 1971 anintermediate station on the base. The feeding assembly also includes apair of calipers adapted at their leading ends to move between open andclosed positions so that in the closed position a workpiece previouslyde- [30] Foreign Appncaflon Priority Data posited at said intermediatestation will be gripped by the calipers and moved forwardly to the pressin which 211 App]. No.: 186,722

Oct. 7, 1970 Great Britain 47,630/70 it is to be deposited. Means areprovided to p the calipers when the feeding assembly is at the end ofits '5 214/8'5 35 2 ,2: forward stroke in order that the workpiececarried by [58] a l8 5 g 1 BB the calipers will be dropped into thepress. The feeding v assembly then returns to its rearward position sothat 7 References Cited the calipers can again pick up from saidintermediate station another workpiece deposited there by said FOREIGNPATENTS OR APPLICATIONS pushermeans on the previous stroke of thefeeding asl,05l,l92 12/1966 Great Britain 214/1 BB sembly.

Primary Examiner-Gerald M. Forlenza Assistant Examiner-George F. AbrahamAttorney-Holman et a].

4 Claims, 7 Drawing Figures [57] ABSTRACT A feed mechanism for feedingworkpieces separately to &

PAIENTEUMJB News sum 1 OF 3 PATENIEDMJB mu SHEET 2 UP 3 To 0w mm Om FEEDMECHANISM FOR PRESSES This invention relates to a feed mechanism for usein feeding a succession of separate workpieces to a power press or thelike, the object of the invention being to provide such a mechanism inan improved form.

In accordance with the invention there is provided a feed mechanism forpresses comprising a base and a reciprocable feeding assembly, saidassembly embodying pusher means comprising a pair of fingers which arearranged so that they each extend in a direction generally parallel tosaid direction of reciprocation and which, on reciprocation of saidassembly, engage the edge of the lowermost workpiece of a stack ofworkpieces which are disposed in use over said base so as to push saidlowermost workpiece forwardly to an intermediate station on said base,there being provided on said base an upwardly extending projection whichis disposed beneath a hopper adapted to hold said stack of workpiecesand which is arranged in use to engage the underside of said lowermostworkpiece at the rear thereof so as thereby to raise the rear of theworkpiece relative to the front, said fingers being arranged so thattheir leading ends are separated to define a slot which receives saidprojection as the fingers are advanced, said feeding assembly alsoembodying a pair of calipers which each extend in a direction which isparallel or substantially parallel to the direction of reciprocation ofsaid feeding assembly, means being provided to close the leading ends ofsaid calipers to grip a workpiece previously depositedon the base atsaid intermediat station when said assembly is at the rearward end ofits cycle whereby forward movement of the assembly from its rearwardposition will result in said calipers carrying the workpiece forwardlyto the die or other tool in which it is to be deposited whilst saidpusher means separates another workpiece from said stack to move saidother workpiece to the intermediate station, further means beingprovided to open said calipers when the feeding assembly is at theforward end of its cycle in order to drop the workpiece carried by thecalipers into the die or other tool.

The invention will now be more particularly described with reference tothe accompanying drawings wherein FIGS. 1 and 2 are respectively apart-sectional side view and plan view of one example of a feedmechanism in accordance with the invention,

FIG. 3 is a side view, on a smaller scale, showing the feed mechanismconnected to a press which is to be fed, and

FIG. 4-7 are diagrammatic plan views illustrating the sequence ofoperation in a working cycle of the feed mechanism shown in FIGS. 1-3.

Referring to the drawings, the press feed mechanism shown therein isprovided with a base or platform mounted on a support 11 which can beattached to a press to which it is required to feed individualworkpieces which may be in the form of flat blanks or which may be inthe form of partly raised components. Said base and its support areconnected together whereby the position of the base can be adjusted asrequired and when in use the upper surface of said base will be arrangedat a vertical height which is level or just above the upper surface of alower die mounted in the press and in which it is required to locate theworkpiece.

' The mechanism is also provided with a reciprocable feeding assembly 12which is movable towards and awy from the press by any convenient meanssuch as pneumatic piston and cylinder unit 13. Said feeding assemblyincludes a pair of fingers 14 and 15 which may be integrally connectedtogether at their rearward ends but which are arranged so that theirleading ends 14a and 15a are free and separated from each other so thata gap or slot exists between the two fingers at least part way alongtheir lengths from the lading end thereof. Furthermore, when the feedingassembly is in its rearward position the leading ends of said fingerswill be spaced some distance rearwardly of a hopper 16 that is mountedin use above the rearward end of said base. It is incidentally to benoted that in the views shown in FIGS. 1 and 2 the workpieces will befed in a direction from right to left and the terms leading and rearwardare to be construed accordingly.

The hopper 16 is conveniently formed by a plurality of verticallyextending pins 17 which serve to locate a stack of workpieces 18 whichare to be fed and on the base is disposed a plurality of strips 19 whicheach extend in a direction generally parallel to the direction ofreciprocation of said feeding assembly, each strip 19 extending from aposition beneath said hopper 16 to a position adjacent to the forwad endof the base, said latter position providing an intermediate station(indicated by reference numeral 20 in FIG. 2) as will be hereinafterdescribed. Furthermore, each of said strips 19 is of tapered form inside elevation so that its thickness diminishes towards saidintermediate station (see FIG. 1). In addition, intermediate said stripsat a position between the rearward ends thereof is a short pin 21 whichis arranged to pass down the'aforementioned gap between the leading ends14a and 15a of said pair of fingers on the feeding assembly as thelatter moves forward. The pin 21 engages the underside of the lowermostworkpiece 18 in the hopper at the rear thereof so that said workpiecesare slightly tilted with their rearward portions being slightly higherthan their forward portions but the leading ends 14a and 15a of saidfingers are arranged so that they will engage the rear most edge of thelowermost workpiece without projecting above said workpiece whereby saidworkpiece can be separated from the stack of workpieces above it. Thus,when the reciprocable feeding assembly is moved by said piston andcylinder unit l3from its rearward position towards the hopper theaforementioned distance betwen the leading ends and 15a of the fingersand the hopper will enable said fingers to acquire sufficient momentumto ensure that the lowermost workpiece will be separated from the stackeven though there by be burrs or oil or grease on the workpieces whichmight otherise cause the lowermost workpiece to stick. The tapered formof said strips 19 will also assist the separation of said lowermostworkpiece. As previously explained the fingers l4 and 15 will carry theseparated lowermost workpiece forwardly to the aforesaid intermediatestation 20 at or adjacent to the forward end of the bse l0 and willleave the workpiece in the intermediate station as the feeding assemblynext returns rearwardly in its cycle of reciprocation. If desired, theremay be arranged at said intermediate station a spring-loaded andadjustable arresting bar 22 which is disposed just above the base 10 andwhich is arranged to frictionally engage the upper surface of theworkpiece as it arrives at the intermediate station in order to ensurethat the workpiece is stopped and retained in the correct position.

The feeding assembly also includes a pair of calipers 23 and 24 whichextend along opposite sides of the mechanism so that each caliperextends in a direction substantially parallel to the direction ofreciprocation of the feeding assembly. Said calipers are pivotablyconnected towards their rearward ends to cross-pieces 25 and 26 whichcan be laterally adjusted in guides 27 in order to vary the lateralsetting of said calipers. Between the pivot of each caliper and itsrearward end there is provided one or more springs 28 which act to pushthe rearward end of the caliper inwardly and therefore the forward endof the caliper outwardly. Thus said springs 28 act to move the forwardend of the calipers to a relatively open position as shown in FIG. 2.The forward end of each caliper is adapted to receive a removablegripping piece 29 shaped to suit the contour of a workpiece which is tobe gripped.

In addition there is provied means for closing the forward or leadingends of said calipers 23 and 24 when desired. Said mans includes alaterally extending bar 30 which is mounted on the reciprocable assemblyso as to be movable through a short distance in a direction generallyparallel to the direction of reciprocation. For example said bar 30 maybe provided with suitable downwardly extending legs which are connectedto said assembly by means of pivots (not shown). There is also provideda pair of L-shaped levers 31 and 32 (see FIG. 2)-which are each pivotedto said cross-pieces 25 and 26 at the ends of said levers indicated byreference numerals 33 and 34 respectively. Depending from each of saidlevers is a pin 35 or 36 which is arranged to engage the forward surfaceof said bar 30 and the other ends of said levers indicated by referencenumerals 37 and 38 respectively are arranged to engage the innersurfaces of the rearward ends of the calipers 23 and 24. Thus, lookingat FIG. 2 it will be understood that if the bar 30 is moved slightly tothe left from the position shown in FIG. 2 then the pins 35 and 36 willbe similarly moved forward to pivot the levers 3H and 32 on their pivots33 and 34 thereby causing the ends 37 and 38 of said levers to engagethe rearward ends of the cal- I ipers 23 and 24 and pivot said calipersso that the gripping pieces 29 will be moved towards each other to gripthe workpiece previously deposited at the intermediate station 20, thesprings 28 being compressed by such pivotal motion of the calipers.

For the purpose of removing said bar 30 to the left there is provided afurther piston and cylinder unit 39 (see FIG. 1) and the piston rod 40of this unit extends forwardly and is connected to a cross-piece 41having end portions 410 and 41b which engage the upper surfaes of levers42 and 43. Each of said levers 42 and 43 is pivoted about a horizontalaxis which in the case of lever 43 is indicated by reference numeral 44in FIG. I and furthermore each lever has a downwardly extending portion(indicated in the case of lever 43 by reference 45), together with anupwardly extending portion (indicated in the case of lever 43 byreference 46). There is also provided a coil spring 47 which surroundsthe aforesaid piston rod 40 so as to engage at one end a part connectedto the bar 30 and at the other end abracket 48 through which the pistonrod 40 can slide. The upwardly extending portions 46 of the levers 42and 43 are connected as by means of bolts to said part connected to thebar 30. Furthermore as will be seen from FIG. l the upper surfaces ofthe levers '42 and 43 at the leading ends thereof are inclined to the Ihorizontal so that when the piston rod 40 carrying with it thecross-piece 42 is moved forwardly from the position shown in FIGS. 1 and2 on actuation of the piston and cylinder unit 39 the ends Ma and 41b ofsaid crosspiece will ride along said inclined portions of said levers 42and 43 to depress the levers which in turn will have the effect ofmoving the portions 46 slightly forwardly thereby similarly carrying thebar 30 forwardly to engage the pins 35 and 36 and pivot the levers 31and 32 as previously described.

The two units 13 and 39 are actuated by a pressurised fluid and arecontrolled by a series of valves which do not form part of the presentinvention. However, for sake of completeness there is indicated in FIG.2 a valve 49 which travels with the aforesaid reciprocable assembly andwhich is connected to the supply of pressurised fluid such as compressedair, said valve 49 controlling the admission of pressurised fluid to theunit 39. Thus, when said assembly is in its rearmost position asindicated in FIG. 2 a part projecting from said valve 49 engages asuitable abutment or stop to set the valve in a condition in which aircan be admitted to the unit 39. At the forward end of the stroke of thereciprocable assembly said valve 49 is engaged by another fixed abutment(not shown) which is arranged to exhaust fluid from the unit 39. Thereare also provided as shown in FIG. I further valves 50 and 51. Thedownwardly extending portion 45 of the lever 43 carries an abutment 52which is adapted to engage the valve 50 when said lever 43 is pivotedconsequent upon the piston rod 40 and cross-piece 41 moving forwardly.The valve 50 controls the admission of pressurised fluid to the pistonand cylinder unit 30 to carry the reciprocable assembly forwardly. Thus,the unit 13 will not be actuated until the unit 39 has been actuated topivot the lever 43 as aforesaid. In other words, the forward ends of thecalipers 23 and 24 will be moved into their closed position to grip acomponent at the intermediate station 20 before the unit 13 is actuatedto carry the reciprocable assembly forwardly.

At the forward end of the stroke of said assembly the valve 49 isactuated as previously explained to exhaust the unit 39. The spring 47then returns the levers 42 and 43 to the positions indicated in FIG. Iso that the bar 30 will be moved to its relatively rearward positionthereby permitting the forward ends of the calipers to open under theinfluence of springs 28. The workpiece or component carried forward fromthe intermediate station 20 by the calipers will thus be deposited inthe die of the press. During this movement of course another componentor workpiece will have been separated from the bottom of the stack inthe hopper 16 by the leading ends 14a and 15a of said fingers l4 and I5to deposit said other workpiece in the intermediate station.Furthermore, the downwardly extending portion 45 of said lever 43carries a further abutment 53 which is arranged, after the unit 39 hasbeen exhausted (thereby causing the lever 43 to pivot to the positionshown in FIG. I) to engage said valve 51 which is itself arranged toadmit pressurised fluid to the other end of the unit l3 therebyeffecting return stroke of said reciprocable assembly.

There is also provided yet a further valve 54 which is engaged by a cam55 so that when said cam 55 is clear of the valve 54 (in other wordswhen the reciprocable assembly is at or near its rearmost position) thepress to which the feeding mechanism is attached can be operated,- saidvalve 54 being connected in a hydraulie or pneumatic circuit whichcontrols the operation of said press.

FIG. 3 is a side view showing a feeding mechanism as above-describedattached to a press 56, the mechanism being additionally supported by anadjustable stand 57. FIGS. 4-7 illustrate diagrammatically the variousstages in the feeding cycle. Thus, in FIG. 4 there is initially noworkpiece in the intermediate station indicated by reference numeralwhilst the reciprocable assembly is in its rearmost position. On thefirst forward stroke of said assembly, illustrated in FIG. 5, aworkpiece 18a is carried forward from the hopper by the fingers to theintermediate statin 20 whilst thre is of course no workpiece to becarried forwardly by the calipers 23 and 24 into the die 58. In FIG. 5said calipers 23 and 24 are shown in the closed position just beforethey are opened prior to the return stroke of the reciprocable assembly.In FIG. 6, said assembly has completed its return stroke and thecalipers 23 and 24 have again closed after having been opened on thereturn journey of said assembly before the assembly is again ready tomove forwardly. On the second forward stroke another workpiece 18b isseparated from the hopper and carried forward to the intermediatestation as seen in FIG. 7 whilst the previously separated workpiece 18ais carried forward by the calipers 23 and 24 into the die 58. Thecalipers will then open as previously described to deposit saidworkpiece 18a in the die prior to return movement of the assembly forpicking up of the workpiece 181; and separation of yet a furtherworkpiece from the hopper.

I claim:

1. A feed mechanism for presses comprising a base and a reciprocablefeeding assembly, said assembly embodying pusher means comprising a pairof fingers which are arranged so that they each extend in a directiongenerally parallel to said direction of reciprocation and which, onreciprocation of said assembly, engage the edge of the lowermostworkpiece of a stack of workpieces which are disposed in use over saidbase so as to push said lowermost workpiece forwardly to an intermediatestation on said base, there being provided on said base an upwardlyextending projection which is disposed beneath a hopper adapted to holdsaid stack of workpieces and which is arranged in use to engage theunderside of said lowermost workpiece at the rear thereof so as therebyto raise the rear of the workpiece relative to the front, said fingersbeing arranged so that their leading ends are separated to define a slotwhich receives said projections as the fingers are advanced, saidfeeding assembly also embodying a pair of calipers which each extend ina direction which is parallel or substantially parallel to the directionof reciprocation of said feeding assembly, means being provided to closethe leading ends of said calipers to grip a workpiece previouslydeposited on the base at said intermediate station when said assembly isat the rearward end of its cycle whereby forward movement of theassembly from its rearward position will result in said caliperscarrying the workpiece forwardly to the die or other tool in which it isto be deposited whilst said pusher means separates another workpiecefrom said stack to move said other workpiece to the intermediatestation, further means being provided to open said calipers when thefeeding assembly is at the forward end of its cycle in order to drop theworkpiece carried by the calipers into the die or other tool.

2. A feed mechanism as claimed in claim I wherein the base is providedwith a plurality of spaced parallel strips which serve as guides overwhich a workpiece engaged by said pusher means can slide, said stripseach extending in said direction of reciprocation and each bieng taperedso as to be of diminishing thickness towards the intermediate station.

3. A feed mechanism as claimed in claim 1 wherein reciprocation of saidassembly is effected by means of fluid pressure actuated piston andcylinder unit and wherein said means for closing the leading ends ofsaid calipers embodies a further fluid pressure actuated piston andcylinder unit.

4. A feed mechanism as claimed in claim 1 wherein means are provided forvariably spacing said pair of calipers in a direction at right angles tosaid direction of reciprocation.

1. A feed mechanism for presses comprising a base and a reciprocablefeeding assembly, said assembly embodying pusher means comprising a pairof fingers which are arranged so that they each extend in a directiongenerally parallel to said direction of reciprocation and which, onreciprocation of said assembly, engage the edge of the lowermostworkpiece of a stack of workpieces which are disposed in use over saidbase so as to push said lowermost workpiece forwardly to an intermediatestation on said base, there being provided on said base an upwardlyextending projection which is disposed beneath a hopper adapted to holdsaid stack of workpieces and which is arranged in use to engage theunderside of said lowermost workpiece at the rear thereof so as therebyto raise the rear of the workpiece relative to the front, said fingersbeing arranged so that their leading ends are separated to define a slotwhich receives said projection as the fingers are advanced, said feedingassembly also embodying a pair of calipers which each extend in adirection which is parallel or substantially parallel to the directionof reciprocation of said feeding assembly, means being provided to closethe leading ends of said calipers to grip a workpiece previouslydeposited on the base at said intermediate station when said assembly isat the rearward end of its cycle whereby forward movement of theassembly from its rearward position will result in said caliperscarrying the workpiece forwardly to the die or other tool in which it isto be deposited whilst said pusher means separates another workpiecefrom said stack to move said other workpiece to the intermediatestation, further means being provided to open said calipers when thefeeding assembly is at the forward end of its cycle in order to drop theworkpiece carried by the calipers into the die or other tool.
 2. A feedmechanism as claimed in claim 1 wherein the base is provided with aplurality of spaced parallel strips which serve as guides over which aworkpiece engaged by said pusher means can slide, said strips eachextending in said direction of reciprocation and each bieng tapered soas to be of diminishing thickness towards the intermediate station.
 3. Afeed mechanism as claimed in claim 1 wherein reciprocation of saidassembly is effected by means of a fluid pressure actuated piston andcylinder unit and wherein said means for closing the leading ends ofsaid calipers embodies a further fluid pressure actuated piston andcylinder unit.
 4. A feed mechanism as claimed in claiM 1 wherein meansare provided for variably spacing said pair of calipers in a directionat right angles to said direction of reciprocation.